Sample purging device



Sept. 2, 1969 p. KETELsEN 3,4643" SAMPLE PURGING DEVICE Filed Sept. 22, 1967 //I/I/I/I I I III I/I I/I I I I/HI I I I/I I ILA /NVENTOR Pefer /efe/sen United States Patent O 3,464,271 SAMPLE PURGING DEVICE Peter Ketelsen, Warringtou, Pa., assignor to Manufacturers Engineering and Equipment Corporation, a corporation of Pennsylvania Filed Sept. 22, 1967, Ser. No. 669,880 int. Cl. G01n 1/00 US. Cl. 73-421 1 Claim ABSTRACT OF THE DISCLOSURE A chamber for treating a sample prior to analysis in an oven. In one position the chamber enclosing the sample is placed to receive dry air and in a second position the chamber is placed so that the sample may be transferred to the oven.

In practice one may wish to obtain a measurement of a particular component given off from a heated sample wherein this component is also present in the surrounding atmosphere.

For example, one may wish to measure the moisture given oif by the sample when heated and the measurement is to be made by using a dry preheated gas stream whose passage through a heated chamber carries the moisture with it to an electrolytic cell such as that of Keidel, U.S. Patent No. 2,830,945 whence the current is integrated to give the required measurement in terms of the given sample. In this case the gas can be dry nitrogen.

A significant problem in this regard is that of removing the efi'ect of moisture in the air at the time of the introduction of the sample.

The present invention presents a simple and economic means of doing this by the use -of an auxiliary purge chamber into which the sample is placed and through which dry unheated gas is passed to remove the atmosphere. As explained below, the system is then moved to a position to permit insertion |of the sample into the furnace without the contribution of an error due to the atmosphere. Such insertion can be done very quickly by the use of the present invention and the flow of the heated gas can be cut back to give a negligible error.

Practice vof the present invention enables measurements to be made down to parts per million by weight, this being well beyond the limits attainable by other techniques, it being understood that we are talking here 3,464,271 Patented Sept. 2, 1969 of methods that can be employed by semiskilled personnel, removed fr-om the laboratory, although it should be pointed out that one is hard put to find methods giving comparable results even in the laboratory.

The single figure of the drawing is a cross sectional view vof an embodiment of the invention.

Application of the present invention will be understood by referring to the drawing where 1 is the sample tray which is supported on the metal rod 2 passing through the filter 3 and to the knob 4. The filter 3 is inserted into the tapered st'opper 5 which is undercut at 6 with holes 7 and 7' to a cavity in 5 in the rear of 3. In practice 1 is inserted into the transparent plastic tube 8 mounted on the transparent plastic block 9 while 8 is at the position 10 of unheated gas through the metal block 11 from connector 12. 1 contains the sample under test. In practice a 30 second purge is sufficient after which 9 can be slid down until 8 is in line with the cavity of the heated chamber 15. During this 'operation the screws 13' and 14 hold 9 against 11 because of the springs 16 and 17. The knob 4 can now be pushed in to the point where the tapered stopper 5 enters 15 and seals it against the flow of gas out of the heated chamber along 8. The location of the undercut 6 in 5 places it in the vicinity of the outlet tube 18 so that heated gas in the chamber passes over the sample in 1 then through the filter 3 and the holes 7 and 7' into the undercut 6 and then up into outlet 18 when it passes to the measuring equipment.

What is claimed is:

1. A gas purging system including a wall element onto which is mounted a purge gas passageway and a furnace entrance opening extending therethrough wherein the chamber to be purged is mounted on a second wall element held in spring juxtaposition to said first wall element said mounting permitting the open end of said chamber to be purged to be shifted alternately between said purge gas passageway and said furnace entrance.

OTHER REFERENCES Renshaw: Journal of Chromatography, August 1962, pp. 343-347.

S. CLEMENT SWISHER, Primary Examner 

